KAF6045

You appear to have a street/routing map set installed. Does that unit support topo map sets? May cost a few $$ to get one that can be downloaded (I don't recall if the 100K Topo set on my Garmin eTrex Touch 35t came with it or was a download -- the CN set I'm sure was a download from $$ CDs, and doesn't seem much different from the base maps). The Topo map overlays altitude lines on the street map. I did have to download $$ maps for my older 76CSX (or whatever notation) -- two SD cards for that, one for street maps, and the other for topo colored maps)

With a completely fresh (or very stale) GPS receiver, it can take over seven minutes just to find a strong bird and download the constellation almanac/ephemeris. More time to obtain first position fix as it cycles through the constellation looking for signals (2D position requires a lock on 3 birds, 3D position needs 4 -- 3D position is lat/long/alt/time, 2D is just lat/long/time)

I've not experimented with that "compander" feature -- I'm pretty sure more than one of my units includes it, but unless the manufacturers have agreed on the parameters, each make may have a different level of effect. Best I understand of the feature is that it is a voice compressor on transmit (which will level out ones speech into a narrower higher level -- if you ever encountered a "power mic" on CB it is a similar concept). Then, on receive, it expands the received signal back into the lower levels -- which also pushes down any noise the signal picked up. Suspect said noise might be internally generated by the wideband SoC processing.

In the old days, .675 was an FCC designated emergency channel usable by any licensee for /emergencies/ (this is back when one applied for TWO of the main frequency pairs, and they were listed on one's license -- you could NOT use any other main frequency; if your radio was, as many business radios of the era, only a two-channel radio [A/B toggle switch], and your license did not include .675, you had no access to the emergency frequency. If you specified .675 as one of your two frequencies, then it was available for general use. When I got licensed, the Maxon GMRS 210+3 was a desirable radio: it had the 462MHz interstitials (in 1-7), .675 (as channel 8), and channels 9&10 were "shop" programmable for the two frequencies on one's license. [While FCC regulations specified a radio shop must do the programming, they included the programming manual -- take the back off, press some button to enter #9 mode, rotate dial to select frequency, press button to enter #10 mode, turn dial to select frequency] Repeater vs Simplex was handled by a front-panel button which would toggle the current channel's state. Note the age of my call-sign -- a 3x4 vs the current crop of 4x3.

Many repeaters have the channel frequency (kHz part) as part of their naming. But .577 is not a valid GMRS frequency. .575 would be. I don't see an FP5xx in the repeater list. Unless you mean the Fort Pierce .575... https://mygmrs.com/repeater/2908

The regulation is 50W maximum OUTPUT TO THE ANTENNA. No amplifiers beyond that... (I suppose one could use a 10-15W mobile as the station, with a 5dB or so amplifier mounted on the antenna mast with only a short 1-3ft coax between it and the antenna (6dB with 15W in would be 60W out, illegal! Depending on losses it might take a 6-7dB gain) You use a high-gain antenna. An antenna with 6dBd gain (ie: 6 dB gain compared to a half-wave dipole... about 8.2dBi -- gain relative to the theoretical "isotropic" antenna [a perfect spherical pattern]) receiving, after coax and connector losses, about 40W will emit an EFFECTIVE radiated power (ERP) equivalent to 160W (3dB -> 2x, so 2x2 time 40). That is, the strongest point in the beam pattern will be equivalent to a half-wave dipole fed with an actual 160W. The beam pattern will be fairly thin stretching toward the horizon. Don't expect much coverage above or below the antenna (if the antenna is on a tall tower on a tall mountain you may need to find a variation of phased segments designed to "steer" the pattern downward to reach the intended area of coverage)

The mailing address is where the FCC will send notifications if it receives enough complaints about the operation of the repeater. The repeater must ID so that the FCC can determine the licensee to which the notification is going to be sent.

I could only go by the downloaded documentation... Sounds like the newer firmware brings the GM-30 up to where the Retevis RA85 (freebies with the RT97 at the time) had been (30 "fixed", 30 "user", and supposedly no other memories)... But I couldn't get the programming to stick using an RA85 programmer download (it also didn't allow access to wide/narrow)... Retevis sent me a link to the RA685 programmer -- which is the dual-band Amateur version -- it not only corrected the base programming, but opened up the memory to 128 slots, and I was able to put GMRS repeater (my RT97) configs into those higher slots.

The repeater's FCC-assigned call sign is that of the licensee, not that of some random user. The NO-ID category does not permit random users.

Refer to my edited post... There is a reason 100W Amateur stations use 22-30A power supplies (the 22A linear [transformer] supply my first rig had was only rated for intermittent transmit, I currently use 30A switching supplies). 22A @ 13.8V -> 303.6W, the 30A -> 414W.

Accounting for internal circuit losses -- a 5W output could result in 10-15W input. At 13.8V (nominal running voltage of a vehicle) that would be about 1A of current. USB provides 5V, so you are already looking at some voltage converter circuit. 15W at 5V means a 3A current draw (which would be transformed to just over 1A at 13.8/12V). As mentioned, a dedicated USB (fast) charger provides less than 2A at full draw. Unless that "something else" is drawing near the standard 10A lighter socket capability (my prior vehicle had a 10A lighter socket, AND a 20A "power" socket), your best route would be to purchase a socket expander -- available in two or three (maybe 4) port forms. https://www.amazon.com/Splitter-Te-Rich-Cigarette-Lighter-Extender/dp/B07919SSGH/ref=sr_1_7?keywords=12v+extender&qid=1664328184&qu=eyJxc2MiOiI0LjY1IiwicXNhIjoiNC4zMSIsInFzcCI6IjQuMjEifQ%3D%3D&sr=8-7 (Hmmm, actually has a 3A charging port!) https://www.amazon.com/Splitter-Te-Rich-Cigarette-Lighter-Extender/dp/B07919SSGH/ref=sr_1_7?keywords=12v+extender&qid=1664328184&qu=eyJxc2MiOiI0LjY1IiwicXNhIjoiNC4zMSIsInFzcCI6IjQuMjEifQ%3D%3D&sr=8-7

Biggest problem with the RT97 is that it doesn't have an ID capability -- so is limited to the licensee and immediate family (their ID announcement are considered sufficient for repeater ID) (1) is the restriction to "immediate family" category (2) is the requirement that said "immediate family" properly identifies with the license holder's call (so technically, if some family members have their own licenses, to use the RT97 repeater they would NOT be operating under their call, and should not identify with their call).

What do you consider a "diy" channel? Per the manual (which seems to prohibit cut&paste): Channels other than CH1-CH30 can only be scanned and received... This implies that, for repeater access, you can only configure channels 23-30 (RPT-1..RPT-8) (and Appendix D would seem to imply those are already programmed for frequency). Interesting -- the menu system shows an entry for wide/narrow specification (but also that one can not change it for programmed channels, one would have to go to VFO mode... But can one then write the modification into channels 1-30 or are they locked to just Tone settings?). Appendix B only shows operation on 12.5kHz bandwidth, which is FRS bandwidth; true GMRS runs 20kHz bandwidth (in a channel spacing of 25kHz -- if one ignores the interstitials, otherwise channels are 12.5kHz apart -- interleaved: 15, 1, 16, 2, ..., 7, 22) So... In summary. Concur with previous responder... But... The manual indicates that one can not modify tones while in Channel mode. So, again, one has to load the frequencies and tones using the VFO mode, and somehow save those back into the equivalent Channel (even tone scanning can only be done in VFO mode). The manual has NO example of programming channels 1-30 for any changes, nor of repeater programming -- and does not allow transmit in VFO mode, nor for channels 31+. BEST BET: Obtain a K-style* programming cable (Wouxun, Baofeng, Retevis, may be compatible -- you need a cable with the USB<>Serial chip in the cable). Note: if it is a Prolific clone chip, you may need to downgrade the driver -- newer Prolific drivers detect clones and refuse to function with them. Download the programming software. READ the radio and save as "initial settings" so you can restore easily (though a hard reset may do the same). Try to adjust the channels, write to radio, and save for subsequent reloads/edits.

The 805 manual has a noticeable missing section: Battery Charging! From the 935 manual:

These days, most of the big radio-telescopes are really phased arrays of smaller radio telescopes using long baseline distances to produce resolution that a single larger dish is incapable of (Especially since I think Arecibo is (still) out-of-action.

If it is a 1/2wave (dipole of some sort) you actually want to get it AWAY from the ground(plane) as ground reflections will affect the radiation pattern (sending some of your signal upwards rather than sideways). The steel roof may also be a factor -- as it may look like an elevated "real" ground, like a steep mound on average terrain.

Well, one thing to account for: Weather broadcasts are in the 150MHz band -- VHF. Your antenna is specifically tuned for 450MHz band (and maybe even a touch higher since GMRS is 462MHz for receive, 467MHz to reach repeaters). A 1/4wave antenna for Wx would be around 19 inches long, and a half-wave around a yard long. A 1/4wave on GMRS is around 6 inches. Unscrewing the antenna could (hypothetically): 1) lengthen it enough to hit a somewhat resonant 150MHz (though I've never heard of a 1/8wave antenna ? , normally one gets a lower band antenna which is a multiple of wavelengths on a higher band); 2) depending upon how the whip mounts, you might be breaking ground-side contact. As for receiving Weather DX -- If I walk out my kitchen door to the middle of my driveway, I can receive maybe two relatively local Wx stations... If I walk 6 feet in any direction, I receive NONE... 12 feet in any direction and I receive them again... And the pattern repeats. Lay a 12x12 ft grid over my property and I can pick up Wx stations at the grid intersections.

It's an old grand-fathered license -- shows up in the 1997 GMRS repeater guidebook I have. The license is likely much older than that, and predates any digital voice format. Seems to mostly be used by parking lot control -- lots of reports of gates not going up or down, payment machines refusing either credit or cash, at least one mention of the Museum... And I overheard one city user (on analog) explicitly state that the DMR wasn't quite working -- but that didn't stop an afternoon of dit-dit-dit-dit noise (I'm presuming some of that is timeslot breaks; if trying to run DMR over an analog repeater I suspect they'll need to revert to single/no time-slot [Tier 1?] mode, otherwise there's no master timing control).

Note that BTech and Radioddity both have "store fronts" on Amazon; don't know if those are handled by other companies behind the scenes or are actually managed by the named firms. And yes, my DB20G shows a rather drastic slope on output power: 22W in the (unlocked) 150MHz range sliding down to just under 12W on GMRS 467MHz repeater inputs (and 13.5W on the 462MHz simplex channels).

I had to take .575 off my scan list as it seems the City of Grand Rapids is trying to implement DMR on their repeater (while allowing regular FM also)

Also MURS is limited to 2W output -- if you hear someone on MURS you definitely shouldn't need 20W of power (and even 5W is outside of MURS regulations).

Won't be enough as, besides BTech, Retevis and Wouxun also have LED flash light mode (and some even have flashing mode). I even have some old bubble-pack pre-2017 FRS/GMRS units with LEDs (on the bottom -- which could be more useful in the dark to illuminate the path while one is still using the radio function)

He also mentioned just having the control panel (face plate) in said room. That should mean the cable just passes audio (speaker/mike) and control signals -- no RF. "screen room" is a bit ambiguous.. It could mean a "screened"/"shielded" room -- or as I first interpreted it, a dedicated room for display/control-monitors, keyboards et al. Using an antenna switch (in reverse) can be a risk as they don't have perfect isolation -- some of the power going from radio A can leak into radio B, and if the attenuation between ports A and B isn't sufficient, the leak could damage the non-selected radio. After all, receive circuits are expecting milliWatts or less; even 1 Watt leakage is massive.

Pre-2017 reorganization. Current FRS regulations are Which is what the pre-2017 combined FRS/GMRS units tended to fit (naturally, my oldest bubble pack units came out on the GMRS side of the regulations after 2017 -- one set has three power levels with H approaching 5W; other set has repeater access capability, though only around 2W out). True FRS unit are restricted to NFM on all channels, NFM would be optional on true GMRS (except as noted below) GMRS now has access to "8-14" with the 0.5W NFM restriction, 5W on "1-7", and 50W on 15-22 (and repeater pairs).

I have both, along with Diamond SX-200 (which covers HF-VHF), along with two MFJ antenna analyzers (with limited capabilities on UHF).. My concern was that, with both high and low power tweaks (I'm presuming those apply to forward and reverse, respectively) in the Surecom -- which is proper? The VNA may show actual SWR, but that SWR is the result of comparing forward and reflected power, and that makes for a spectrum of adjustments in the Surecom -- do you accept the forward (high) power reading and tweak the reflected (low) power up/down, do you tweak the forward to display /rated/ output power of the radio, and THEN tweak the reflected until the SWR matches the VNA, etc.. (The SX-200 is a single needle meter, in which one uses a "Cal" position to set whatever the actual forward power may be to "full scale", then flip the switch to "SWR" which is essentially based on the reflected power scaled by the "Cal" dial -- similarly, forward and reflected power are separate switch positions [it also has a peak/avg button]. While it doesn't reach UHF, I can at least compare it against the MFJ, and get similar readings from my 100W TS-2000 on 2m (both show ~85-88W - so two meters separated by decades and by different manufacturers would appear to have similar miscalibration, or my TS-2000 is under performing on 2m). I bought the NanoVNA mainly because I'm tired of doing manual frequency sweeps with the MFJ antenna analyzers. ADDENDUM: While there is a screw for the battery compartment, I suspect gaining access to sensor board would require mangling the back specification label (metal, not paper). Said label states 0-120W +/- 5%